This invention generally relates to a device which allows the latch of a door to be retained in an open position by securing the knob of the door in a latch releasing turned open position. More specifically, the invention relates to a device which will frictionally engage the door knob and door itself so as to retain the door knob in its turned open position to thereby retain the latch mechanism in an open condition to prevent the door from latching when closed.
Under many circumstances, it may be desirable to render the latch of a door inoperative to prevent latching of the door when in a closed position. For example, the elderly or physically impaired may find it difficult to turn the knob of a door to unlatch a door for opening. At the same time, it may not be desired to permanently render the latch of the door unusable, as latching of the door may be desired for security purposes or to assuredly maintain the door in a closed position.
In another aspect, there have been developed automatic door openers of various types. In a commercial setting, the doors of a store or the like may not have a knob and latch system as is found on household doors or the like. In these situations, the door may be simply locked by a deadbolt or similar mechanism, which after retraction will allow an automatic door to operate accordingly. In such a situation, there is no need for means to retract a latch mechanism to affect opening of a door. On the other hand, in a door having a latch system and turnable knob to retract the latch, an automatic door opening device will only be operable if the door is maintained in an open condition to prevent latching thereof or if the latch can be selectively unlatched upon operation of the opening device or if the latch is rendered inoperative. A door opening the closing device suitable for use in the home or commercial environments is shown in co-pending U.S. application Ser. No. 394,561, now allowed, which includes a latch control means acting to automatically unlatch the door upon initiation of the device to open the door. In this respect, the particular latch release mechanism used with the opening device may be of any known configuration to be electrically actuated by the device. Various latch release control apparatus are known such as is shown in U.S. Pat. Nos. 3,188,129, 3,910,617, 3,804,442, and 4,529,234. Although providing an electrical release mechanism for the latch assembly of a door enables selective operation of the latch when desired, such systems add significantly to the expense and complexity of a door opening assembly and may be susceptible to malfunction thereby resulting in failure of the system and additional costs.